Archive for the ‘Marine Species’ Category

A whale shark seen with a swimmer off Colombo. Pic courtesy Nishan Perera

As the sightings of whale sharks increase in our waters, experts say the world’s largest fish needs to be protected.

“We still know very little about whale sharks, but the fish is already ‘endangered’ and highly threatened by both target and bycatch fisheries,” says marine biologist from Blue Resources Trust, Daniel Fernando. He made the remarks at a lecture at an event organised by Sri Lanka Sub-Aqua Club this week.

The blue whale is the largest creature on Earth, but since it is a marine mammal, the crown of being the largest fish goes to the whale shark. A whale shark can grow up to 40 feet (12 meters) or more and weigh about 20 tons. The average whale shark is 8 metres long, but the ones found in Sri Lankan waters are 6-7 metres according to Mr Fernando.

Scientifically classified as rhincodon typus, the whale shark called ‘mini muthu mora’ in Sinhala is in fact a species of shark. But unlike other sharks, they do not have teeth and they are filter feeders that depend on plankton. By opening their huge gaping mouths closer to the surface, they scoop in these plants along with any small fish.

Divers have reported more sightings in the seas off Colombo.

Nishan Perera, a marine biologist who has made regular dives in the oceans off Colombo, reported more whale shark sightings in February and March when these fish are seen in our waters. “Two or three whale shark sightings during this period is normal, but this year there were dozens of encounters,” Mr Perera said.

A giant whale shark seen in colombo seas (c) Sanjeev de Silva

The Maldives is a famous destination for whale sharks and queries revealed a lower number of encounters in Maldivian waters when there was an increase in our waters said Mr Perera. The whale sharks have spots on the body and its pattern is unique for each individual. So, the Sri Lankan marine biologists also shared the photos of the whale sharks seen in Sri Lankan waters with other international whale shark databases to verify where they are from.

It could be the same individuals seen in different occasions, but the fact that they are seen more often means that the fish that are used to passing through our waters are staying a little longer than previous years.

Author of the “Sharks of Sri Lanka”; Rex I De Silva says the large number of recent sightings baffle him. He says these fish usually migrate to areas rich in plankton. These areas are where there is an upwelling of nutrient-rich water from the depths. So, it is possible that, fuelled by changes in hydrologic factors, such upwellings are now occurring with greater frequency in our coastal waters. Upwellings encourage the growth of plankton which, in turn, attracts other plankton feeders such as fish. Whale sharks also feed on fish (especially small scombrids) which are attracted to the plankton.

Changing oceanic patterns due to global warming is another reason according to the expert. However, these are just suggestions as to why whale shark sightings have become common in recent years. We just do not have sufficient data to draw firm conclusions, cautioned Mr De Silva.

Howard Martenstyn, another expert, points out that there are more nutrients in the western seaboard compared to 2016 as evidenced by increased rainfall and river outflows and that may explain more whale shark sightings. Mr Matenstyn also reminds us that the number of sightings in the same area does not usually equate to the number of whale sharks, highlighting the need for more supporting data and investigations.

The whale shark is a gentle giant, which allows divers swim with them. They pose no danger to humans but an accidental blow from the powerful tail can cause injury. Experts advise keeping a minimum distance of 1.5 metres from the front of the body and 3 metres from the rear.

The whale shark takes about 15 years to mature to reproduce and is vulnerable to overfishing. Sri Lanka passed laws banning the catching of whale sharks in 2015, but awareness of such regulations, along with implementation, is often lacking points out Daniel Fernando.

Experts urge Sri Lanka to join global effort to protect sharks
Sharks have slow reproductive cycles and cannot be fished at levels similar to other fish. But sadly, Sri Lanka is among top 20 shark killing countries ranked at 14th place according to a 2013 report by the wildlife trade monitoring network TRAFFIC and the Pew Environment Group.

The Fisheries Department says that steps have been taken to protect sharks. Five species are protected by law, including three species of thresher sharks, oceanic-white tip shark, and the whale shark. The department says it even distributes tools such as de-hookers and line cutters among fishermen that can be used to release sharks caught in nets or hooks.

But more needs to be done to protect these apex predators in our ocean near the top of the marine food chain and help regulate populations of species in the marine ecosystem, the experts say.

Sharks are also important to the economic survival of the fishing industry and have the potential to attract tourists. So Sri Lanka should follow the example of the Maldives and other nations to support international conservation and protection of sharks, marine expert Howard Martenstyn, says.

Several species of shark migrate into different areas of oceans governed by different countries. So to protect them, the Convention of Migratory Species initiated a memorandum of understanding on the conservation of migratory sharks in 2010. Sri Lanka has not yet signed this, but marine experts say this would be a great step forward in recognising the value of sharks within our national and regional waters, points out Daniel Fernando.

In the animal kingdom, there are species that look alike, or ‘hybrids’, between two or more creatures. Marine creatures with such features often go unnoticed, but the fish caught in nets off the southern coast puzzled many as it appeared like a shark and a ray (‘mora’ and ‘maduwa’ in Sinhala, respectively).This strange fish had ‘shark like’ fins and tail. However, its head looks like a ray and had ray-like ‘wings’. The fish photographed by Devsiri Peiris last month is said to have been caught accidentally in a fishing net. It is about five feet long and a male.

“It is a fish we call ‘shark ray’, known by fishermen as ‘thith mora’’’, says Rex I. De Silva – an expert on sharks. “Despite its Sinhala name, it is not a shark but a ray,’’ he says.

The shark ray is scientifically named as Rhina ancylostoma also called mud skate as it is found in sandy bottoms doing bottom feeding. Due to the shape of its head the fish in this group is also known as ‘guitarfish’. The one caught is a Bowmouth Guitarfish. According to literature, this large species can reach a length of 2.7 m (8.9 ft) and weight of 135 kg (298 lb). They are found in depths of up to 90 m (300 ft).

Shark expert, Mr de Silva says the species is rare. “Nevertheless the species appears in very small numbers from time-to-time in fish markets. I have seen them at Negombo, Kalmunai and Kirinda markets,” Mr De Silva says.

Gal malu, or rock fish, are generally popular in the country and these include varieties of grouper and parrot fish (girawa).

The National Aquatic Resources Research and Development Agency (NARA) initiated a study in January to asses status of ‘edible reef fish’ commonly known as ‘gal malu’. The study will take about a year, the Sunday Times learns.

“The size of fish caught is smaller on average. Fishermen now must use more fishing gear to catch a similar volume of fish they caught a decade ago. This alone indicates the depletion of edible ‘gal malu’ populations,” points out Dr Sisira Haputantri – the head of Marine Biology Division of NARA.

The killing of a human-sized humphead wrasse (cheilinus undulates) in Unawatuna by spearfishing two weeks ago helped intensity demands for a ban on spearfishing.

The Director General of the Department of Fisheries & Aquatic Resources, M C L Fernando, said a proposal to ban spearfishing is now being reviewed by the government’s law drafters.

Action has been also taken to ban the fishing of tomato grouper (cephalopholis sonnerati) – a beautiful coral fish known as ‘ran thambuva’ locally. Tomato grouper inhabits holes in the reef with cleaner shrimp and helps maintain the hiding places by fanning out sand. Scarlet shrimp and painted shrimp are high value items in the ornamental fish trade and without the groupers, the shrimp populations would die out.

Many other reef fish are threatened by overfishing and high consumption locally and overseas. The SundayTimes reported last week that the Sub-Aqua Club has appealed to the Minister of Fisheries to protect 15 large coral fish. Most of them are groupers and listed under threatened categories in the International Union for Conservation of Nature Red List with the humphead wrasse being listed as ‘endangered’. However, the DG of the Fisheries Department is not convinced of the threat facing these fish and insists on a study to assess the situation.

But marine biologists and divers that the Sunday Times contacted say their encounters with large reef fish are becoming rarer, which itself is an indication of their vulnerability.

Meanwhile, news emerged this week that the Fisheries Minister Mahinda Amaraweera wants to ban the fishing of parrotfish.

When contacted, the minister also said that the fishing of parrotfish no smaller than 500 grams will not be allowed. But, the Sunday Times found out from the DG of Fisheries that there are no immediate plans to ban the fishing of parrotfish and that such a move would be based on the study on reef fish.

The parrotfish inhabits coral reefs and feed on algae growing on the reef. There are about 10 different species of parrotfish in Sri Lanka. Thankfully, locally there is not much demand for it as a food fish.

Unfortunately though, this beautiful fish is in high demand among Chinese. There are suspicions and fears that the appearance of parrotfish in local supermarkets is to cater to demand from increasing numbers of Chinese living and visiting Sri Lanka.

Arjan Rajasuriya Coordinator, Coastal & Marine Programme IUCN Sri Lanka emphasises that fish stocks of Sri Lanka need to be monitored regularly, especially to check whether demand has grown in recent years for species that had not been sought-after previously.

He also notes that reef fish are threatened due to pollution, invasive alien species, climate change, and illegal fishing methods such as dynamiting. Conservation is necessary before its too late, he said.

An international study has placed Sri Lanka among top 20 countries that catch sharks.

Noting that these 20 countries account for 80% of the world’s annual shark catch, a report based on the study puts the survival of many shark varieties in their hands.

Shark fins laid out to dry in Negombo

This report titled “The future of the Shark: A Review of Action and Inaction” was produced by the wildlife trade monitoring network TRAFFIC, and the Pew Environment Group. It analysed shark, ray and skate catch data provided by countries to the Food and Agriculture Organisation (FAO).

TRAFFIC’s Global Marine Programme Leader Glenn Sant said, “Countries need to take action to stop the decline in shark populations and help ensure that the list of species threatened by overfishing does not continue to grow.”

Placing Sri Lanka in the 14th place, the report says Indonesia, India, Spain and Taiwan account for more than 35% of the total shark catch. Though Sri Lanka’s contribution to the global catch is only 2.4%, it is still a significant quantity, given the size of the country and its fishing fleet.

Sharks are particularly vulnerable to overexploitation because of their biological characteristics of maturing late, having few young and being long-lived. Worldwide, shark populations are in decline due to unregulated fishing, much of it to meet the high demand for fins.

About 60 species of sharks populate in Sri Lanka’s waters and its exclusive economic zone. According National Aquatic Resources Research and Development Agency (NARA) fish expert Rekha Maldeniya, silky shark leads Sri Lanka’s shark catch. About 70% of the catch consists of silky shark, followed by thresher shark and hammerhead sharks.

Thresher shark, identified as a threatened species, was caught despite a government ban.

Oceanic white-tip shark, blue shark and mackerel shark are the other common species with commercial value, according to the Fisheries Department.

The Convention on International Trade of Endangered Species (CITES) held in Bangkok, Thailand in March this year declared the oceanic white-tip shark, three species of hammerhead sharks and manta rays as protected species. Accordingly, trade of these species requires a CITES permit. As a signatory to the convention, Sri Lanka will also need to take measures to regulate fishing of these species.
In Sri Lanka, the sharks are mostly a by-catch, says Dr. Maldeniya. But there are dozens of fishing boats particularly targeting sharks for fins which have a big export market. The long-line fishing method — that has several hooks attached to a line — is being widely used for shark fishing.

The Sri Lankan section of the report says that sharks are also caught as by-catch in bottom-set gillnet fishing, the bottom-set long-line fishing and the beach seine fishing.

Dr. Maldeniya says Sri Lanka has started a National Plan of Action for sharks. This has been initiated with assistance from the Bay of Bengal Large Marine Ecosystem (BOBLME) Project. The project aims at identifying shark species, their composition, possible breeding grounds and other factors which are relevant to shark conservation.

The NARA expert says the project also recommends policies to protect not only sharks but also the livelihoods of fishermen.

Sharks play a crucial role in sustaining the ocean environment. Where shark populations are healthy, marine life thrives; but where they have been overfished, ecosystems fall out of balance.

Malaka Rodrigo �reporting �from Bangkok – Sri Lanka maintained total silence on how it voted as an important proposal to protect sharks and manta ray species was passed earlier this week at the 16th Conference of the Parties (COP16) of Convention on International Trade of Endangered Species of Wild Fauna & Flora (CITES) in Bangkok.

Activists canvassing for the shark vote at the Bangkok conference

The proposal was passed with a clear majority after some tense proceedings as countries opposing the decision could canvass support from other countries and call for a re-vote. As expected Japan backed by India and Gambia challenged the decision on oceanic white-tip shark while China and Grenada had attempted to reopen the debate on the listing of the three hammerhead sharks. However, there was no revote in spite of attempts to reopen the debate.

It was widely speculated that China and Japan would pressurise Sri Lanka to vote their way but, Sri Lanka’s delegation head and Wildlife Conservation (DWC) Director General H.D. Ratnayake declined to comment on Sri Lanka’s position on the basis that it was a secret ballot.Following the favourable vote these species have been listed under Appendix-II of CITES and accordingly these species of sharks and manta rays will have to be traded with CITES permits following proof that they were harvested sustainably and legally.

Mr. Ratnayake said his department would work closely with the Fisheries Department and NARA to protect these species in Sri Lankan waters. He said this was just the beginning in an area where much more had to be done to protect Sri Lanka’s marine species. The Sunday Times last week reported on the importance of Sri Lanka voting in favour of the proposal to list oceanic white-tip shark, three species of hammerhead sharks and two species of manta ray. These are threatened species in Sri Lanka’s waters because of a big export market for their dried fins and gill plates.
(Please also see reletated )

The banned ‘laila’ net is steadily killing off the dolphins, writes Malaka Rodrigo�

Illegal fishing practices used in the seas off Kalpitiya have resulted in the death of more than 40 dolphins, investigations reveal. The dolphin casualties have sparked demands for a rigorous crackdown on banned fishing methods.

Dolphins are frequent casualties of illegal fishing methods

A sandbag used for a Laila net dropped among shallow corals

Last week, Police arrested 14 fishermen and confiscated six boats and banned fishing equipment, including what is known as the “laila” fishing net. The Police were acting on a directive from the Fisheries Ministry based on complaints from members of the Kalpitiya fishing community.

The “laila net” was the cause of the death of the 40 dolphins, Dr. Sayuru Samarasundara, chairman of the National Aquatic Research and Development Agency (NARA), told the Sunday Times.

The laila net is a type of large ring net or purse seine net used to encircle large shoals of fish. It can be closed at the bottom to maximize the catch. This fishing practice has been condemned as destructive, as it entraps both large and small fish and can result in the elimination or extinction of a fish species in targeted fishing areas. Dolphin groups are known to associate closely with tuna and related species such as skipjack tuna and bullet tuna. Because dolphins feed on small tuna-related fish, fishermen follow dolphin groups in order to locate high-value fish, explained NARA fish expert Dr. Rekha Maldeniya.

A laila net operation involves the use of between five and six boats and a team of fishermen as well as divers and snorkellers. It is said that the force of the fish struggling to break through the net is so great that the fishermen use dynamite to kill or stun the fish. Dolphins are regular casualties of this fishing method.

Kalpitiya sources say the destructive laila fishing method has been in use for some time, and that dolphins are a frequent by-catch. As dolphins are a prohibited catch, laila fishermen are careful to dump the dead dolphins at sea. Local sources say the dolphin carcasses are sometimes tied to sand bags and dropped so that they sink to the sea floor.

Marine biologists say laila nets are laid in close proximity to the Bar Reef Sanctuary, an important ecosystem in the Kalpitiya area. The Bar Reef was declared a sanctuary after extensive work conducted by NARA under environmentalist Arjan Rajasuriya.

Mr. Rajasuriya said laila nets were not around at the time he was doing his Bar Reef research in 1989 and the early 1990s. The laila net came into use only in the late 1990s. Mr. Rajasuriya told the Sunday Times that the Bar Reef is one of the country’s most diverse marine habitats and requires protection. “But, sadly, all the larger fish are gone, and the destructive laila net is the chief culprit,” he said.

The destructive impact of laila netting goes far beyond killing dolphins, Mr. Rajasuriya said. This form of fishing basically targets spawning aggregations of fish. Many species of fish, especially those that live in groups, come together seasonally to spawn. Jack (paraw), snapper (atissas) and barracuda (jeela) often aggregate in Kalpitiya waters days before the real spawning, travelling as a “large ball of fish.” One laila net is sufficient to wipe out whole colonies of these fish. Most of the larger fish are now gone, Mr. Rajasuriya said.

Environment and wildlife activists are working with tour operators to push for the protection of the country’s marine resources. Kalpitiya Dolphin Watching is lucrative business. Tourists go to see the dolphins and the underwater corals. If dolphins continue to be killed and corals continue to be destroyed by dynamiting, tour operators will have little to show tourists. Tourism operators should be at the fore in action to protect the Kalpitiya ecosystem, Mr. Rajasuriya said.

Displaced Mannar fishermen brought laila net during war years

Laila netting is not a traditional fishing mode in Kalpitiya. According to locals, the laila was introduced by Mannar fishermen who were displaced during the war. �Although the war is over, the Mannar immigrants continue to operate on the northwest coast where the fishing grounds are much richer than on the east coast.

Residents say the Mannar fishermen operating in the area have political backing. The indigent Kalpitiya fishing community is against the laila fishing mode, and has held several protests to demand preventive action.

Back in 2004, Kalpitiya fishermen held a satyagraha to condemn laila net fishing. Another sit-in was staged two years ago in Kalpitiya town.�A catch made with a laila net can weigh up to 8,000 and 10,000 kilograms. To get such a large catch on board can take up to one hour, ample time for the authorities to conduct a raid on the operation.

For now, however, the Department of Wildlife Conservation has no designated marine unit or even a boat to conduct a raid. The Sri Lanka Navy too has taken no action in regard to illegal laila net fishing. zUpali Mallikarachchi of the Marine and Coastal Resources Conservation Foundation says sustainable fishing methods should be strengthened and supported.

Not only elephants and leopards, but lesser known species such as freshwater crabs, that are jewels of Sri Lanka’s biodiversity, need to be protected, say experts.

On January 14, Customs at Katunayake Airport detected a consignment of 125 live freshwater crabs to be exported along with a consignment of other ornamental freshwater fish. The exporter who pleaded ignorance of their importance, was let off with a severe warning.

Custom’s Biodiversity Protection Unit’s Samantha Gunasekara confirmed this as the first detection of freshwater crabs, which were sent to the Dehiwala Zoo. Mr. Gunasekara, an expert on freshwater fish, said, though it is certain the crabs were collected from the wild, it was not prudent to return them to the wild, without knowing the exact location of their origin.

Many of Sri Lanka’s freshwater crabs show very restricted range and could lead to contamination of their pedigrees, as they could also be carrying diseases, hence the decision not to return them to the wild.

Sri Lanka’s freshwater crabs show the highest endemism for any group of animals, where, out of a total of 51 species, 50 are found only in our country. Up to 1994, only eight species of freshwater crabs were recognised as being from Sri Lanka, until an extensive exploration carried out by the National University of Singapore and the Wildlife Heritage Trust of Sri Lanka, resulted in the discovery of many new species, bringing this number to 51. At that time, all 51 freshwater crabs were endemic to Sri Lanka, elevating Sri Lanka as a Global Biodiversity Hotspot.

But it is unfortunate that this fauna group of high endemism also faces the highest threat of extinction. Nearly half the freshwater crabs – 23 species, are point endemics found only in single locations, making them extremely vulnerable to habitat loss, degradation and pollution. Most of them are restricted to Sri Lanka’s wet zone, where habitats are under the heaviest pressure. Assessing these risks, the recently launched National Red List marked 34 of them as “Critically Endangered”, with another 12 as “Endangered”.

Dinesh Gabadage and M.M. Bahir, perhaps the only experts on the Sri Lankan freshwater crabs, in their “Conservation Status of the freshwater crabs in the National Red List 2012,” suggest the need for urgent conservation actions.

According to these experts, many of the freshwater crabs occur outside the protected area network in private lands. Therefore, they suggest the need to engage the local community to protect these declining species, especially the point endemics that are restricted to single areas.

They also suggest maintaining a captive population for the Critically Endangered species. Perhaps, the stock handed over to the Dehiwala Zoo is a good opportunity to start a captive breeding programme, or Ex-situ conservation mechanisms.

Considering their rarity, there could be a demand for Sri Lanka’s freshwater crabs, from foreign collectors and breeders, warns Samantha Gunasekara.

As the collection from the wild adds to the list of their threats, he emphasises the need to strengthening the Fauna and Flora Ordinance further, to protect these kinds of neglected, yet highly important species that are the gems of Sri Lanka’s Biodiversity.

Last week, this blog reported about mass influx of Dragonflies that usually occurs in this period of time. This week, the fishermen got a bumper harvest from fish aggravate in coastal waters..!!

Reports from East coast indicated that the fish has come to areas near shore giving bumper harvest

Malu, Malu, Malu: Thousands of fish were washed ashore yesterday due to changes in the weather pattern and the temperature of the seabed. Children and other residents of Beruwala are seen collecting the fish, dead or alive, with experts saying the fish was not harmful for consumption. Pic by S. Siriwardena/SundayTimes

to the fishermen. This is been reported mainly in Kanthamkudi and other areas in Batticaloa, but our correspondents from Beruwala too reported lots of fish been found making it maritime for fishermen.

But this has puzzled general public where many fears it is a sign of an incoming disaster. SundayTimes asked the Oceanography experts to find out the reason for this phenomenon. Dr.K.Arulananthan – the head of National Institute of Oceanography and Maritime Science based at NARA said has been caused due to changing patterns of Oceanic Currents.

Sri Lanka is now experiencing the second Inter Monsoon Rains. According to Dr.Arul, During the South Western Monsoon, the East Indian Coastal current flows from Arabian see toward Bay of Bengal via Southern tip of Sri Lanka. But on the North-western Monsoon; the direction of this East Indian Coastal Current reverse and it happen during the Inter-monsoon season. This brings cold water from Bay of Bengal region and this change of temperature assist growing of Algae and Planktons that leads to algae bloom. Little fish gathers to feed on these microscopic plankton and even big Pelagic fish lives in open seas follows the smaller ones making this present fishing frenzy in many areas, explained Dr.Arul.

The Sardines or Keeramin and Skipjack Tuna are the most notable fish gathered in numbers during past few days. The said phenomena is more applicable for pelagic fish, comments Dr.Arul. The expert also explains another possibility of getting some of the dead fish washed ashore. The Algae is also perform Photosynthesis which consumes the Oxygen in the water. In the waters where Algae bloom, the fish find lack of Oxygen and many dies. Some of these dead fish washed ashore while others sunk deep down to bottom. The decaying bodies of fish at the bottom deplete the Oxygen in that region which affect the bottom dwelling fish like Eel or Ray fishes.

This year Sri Lanka experienced a delayed South West monsoon and perhaps these climatic changes aggravated the differences of the oceanic current to make it more observant. However, Dr.Arulananthan calls it is a normal phenomena and nothing to worry. But the Climate Change may bring more such abnormal changes of weather patterns that leads to phenomenas like this in the future fears the experts.

Many fears that this could be bad omen remembering that just before 2004 Tsunami, loads of fish aggravated in similar manner. Dr.Arul reminding that Tsunami came in December and this phenomenon of changing of East Indian Coastal Current occur during October or November that could have triggered fish aggravation in 2004. He also says the underwater earthquakes might make bottom dwelling fish lives in the deep to migrate to other regions in sea via Oceanic currents, but the fish caught during last few days are not abnormal species, but the common ones usually found in our oceans.

However, it is interesting to know that how the changes of climatic patterns effects the animal behavior as only last week SundayTimes reported about a Dragonfly Migration that follows Inter Tropical Convergence Zone which falls on the same time period across Sri Lanka.

Beruwala too records mass fish death

Meanwhile a large scale of fish deaths was also reported in Beruwala. Hundreds of fish were found dead in a stream called ‘Sellie Ela’ according to NARA sources. This waterway is getting full with water brought in by rain and the nutrients brought in with water increased the algae growth making an algae bloom. Dr.Rekha Maldeniya of NARA said when that the algae emits oxygen during day time when doing photo synthesis and emit carbon dioxide at night while absorbing oxygen in the water. So this deplete the Oxygen in water killing the fish. It is also reported that the water in this ela is now turned into blackish, and Dr.Maldeniya said it is due to died algae. These algae when dead can emit toxics which cause the death of fish. Dr.Maldeniya said these 2 factors were the reason for Beruwala fish death.

Some of these dead fish ended up in the sea.

Climate Change Shrinks Fish Size, Says New Study

A new scientific study shows that Climate Change will shrink the size of fish by 14-24%. This too links to the level of Oxygen in the water where scientists say the increase of temperature will reduce the Oxygen in the water. The researchers have studied change of body size of some 600 species based on models between 2001 and 2050.

The fish stocks around the world are already being depleted due to overfishing. Climate Change due to global warming will also make the ocean acidification that impacts the fish and this study will be another blow. The researchers pointed out that worst impact could be observed in the tropical regions, so countries like Sri Lanka will be expected to be badly effect.

The popular edible fish known to local fishermen as “modha” or “koduwa”, and recently declared endemic to Sri Lanka, has been given a scientific name with a local flavour – Lates lakdiva.

In an article that appeared last week in the scientific journal Zootaxa, Sri Lankan scientist Rohan Pethiyagoda has established that the koduwa is a marine species, not a freshwater fish, and that it is unique to Sri Lanka. The Lankan sea bass was earlier thought to be the same species, Lates calcarifer, found in waters across Asia and all the way to northeast Australia.

Unlike the Lates calcarifer, which live in freshwater rivers and descend to estuaries to breed, the Sri Lanka koduwa or sea bass live in coastal waters and breed in estuaries.

“This was pointed out to me in the early 1990s by the naturalist Cedric Martensteyn,” the Sydney-based Mr. Pethiyagoda says. “I put the Sri Lankan and the Australian specimens side by side to see if they were the same.”

In the article, Mr. Pethiyagoda and fellow scientist Tony Gill demonstrate that the Sri Lankan koduwa is not Lates calcarifer but a different species. Because the fish was discovered in Lankan waters, the researchers have named the koduwa Lates lakdiva.

The Sri Lankan fish is smaller and more slender than its larger, more widely distributed cousin, and there are other anatomical differences. Koduwa figures prominently on restaurant menus in Sri Lanka. Diners prize it for its succulent white flesh, and anglers seek it in fishing spots such as Bolgoda Lake and the Madu Ganga.

Lates calcarifer is known in Australia as barramundi and is the country’s most popular freshwater fish. The Australian fish can reach a weight of over 40 kgs and sell for Rs. 4,000 a kilo. The Sri Lankan fish is much smaller. A five-kilo koduwa would be considered big.

The research paper also described another species of barramundi found in Myanmar. Researchers named it Lates uwisara, in honour of Ven. U Wisara, the Buddhist monk who gave his life in the struggle for Myanmar’s independence from colonial rule.

Croc in Wellawatte Canal photographed in 2007 December while basking at Canal Bank (c) Mike Anthonisz

Villagers have spotted a crocodile in the sea along the Wellawatte-Dehiwala coastline. The animal has been seen on several occasions, but animal activists say there is no cause for concern – this is no invasion by a swarm of crocs but a case of a lone reptile drifting harmlessly in the water.

Philip Weinman has seen the crocodile on two occasions, in the sea around Dehiwala. The first time was in mid-February, around six in the morning, when he was out at sea in his boat fishing. The second sighting was a week later, in the evening. He tried to take a photograph, but the croc disappeared when the boat approached it. Mr. Weinman estimates the reptile at between 6 and 8 feet in length.

The crocodile photographed in Colombo Dockyard

Canal system in Colombo where crocs get access to sea

Mr. Weinman is a member of the Anglers Club, and deep sea fishing is a pastime. “I have been fishing for more than 25 years, and this was the first time I saw a crocodile in the sea.”

The Dehiwala fishing community has reported several sightings. Late last month, a swimmer entered the Dehiwala sea only to race back to shore on seeing a crocodile in the water. Eyewitnesses agree the crocodile has been a passive, non-aggressive visitor, drifting about peacefully in the sea beyond the line of breaking waves.

Meanwhile, a crocodile was seen over several days in the Colombo Dockyard. The animal was first spotted on February 20. Dockyard employee Rohithe Amarasinghe took photographs and a video. The animal was seen paddling passively around the same spot for three consecutive days. Mr. Amarasinghe, who has worked at the dockyard for many years, said this was the first time he had seen a crocodile in the vicinity.

Animal experts say it is not unusual to see crocodiles in the sea. Most likely, these are salt water crocodiles, known as gata kimbula in Sinhala. Their habitat covers estuaries and lagoons, but they are occasionally found in the sea. The salt water crocodile excretes excess salt from its body. Dr. Anslem de Silva, an authority on crocodiles, says crocodiles would rather avoid than confront humans encountered in the sea.

Dr. de Silva, who is vice-chairman of the Crocodile Specialist Group IUCN/SSC for South Asia and Iran, believes the sea-going crocodile might have come along a canal and ended up on the Colombo shoreline. Colombo has a good canal network system, originally built for transportation during the Dutch occupation. The canals are interlinked and connect different parts of the city and suburbs. The marshes in the western province – Muturajawela and Bolgoda – are among the last hideouts of the salt water crocodile.

A crocodile was spotted in the Wellawatte canal a few years ago. The Sunday Times reported on the crocodile in December 2007 in an article by Mike Anthonisz. Mr. Anthonisz said he saw a crocodile basking in the same spot three months ago. It is possible that the crocodile seen recently off Dehiwala is the same animal, probably disturbed by human activity along the Wellawatte canal or flushed into the sea by heavy rains filling the canals. Crocodiles need time in the sun.

Experts say the presence of a crocodile in the sea around a highly commercialized city suggests urban biodiversity. They hoped the animal would not suffer the fate of the Ragama crocodile, which died after being captured.

Participants in the annual two-mile swim were naturally concerned. The event attracts hundreds of swimmers, who swim from Mt. Lavinia to Wellawatte, a stretch that covers the area where the crocodile has been spotted. The 75th two-mile swim was held last Sunday, March 4 without incident.

Dr. Anslem de Silva said it was unlikely that a crocodile would want to be near a noisy event such as a swimming competition, which involves hundreds of people, as well as boats that ride close to the swimmers. All that activity would scare a crocodile away.

The sea urchin population in many coastal areas is on the increase, and this could have a negative impact on recreational activities associated with the coast. In certain areas, hundreds of these spiny creatures cover small areas of rock floor in shallow waters, presenting a risk to bathers, divers, and anyone who likes to go wading in the sea.

A sea urchin (Diadema Savignyi)

A recent visitor came out of the sea with more than 400 sea urchin spines stuck in his body, according to marine biologist Dr. Terney Pradeep Kumara. In another incident, a foreigner who had gone snorkelling in urchin-infested waters had to be taken to hospital to undergo surgery under general anaesthesic. Tourism could suffer a blow if the urchin invasion continues.

The sea urchin (ikiriya in Sinhala) is a spiny, hard-shelled creature that lives on the rocky seafloor, usually in shallow waters. The globular marine invertebrate has long sharp spines all over its body, and uses these needle-like growths to ward off predators. The spines inflict a painful wound if they penetrate human skin. The spines break when they go through flesh, which has to be cut open to remove the spine fragments.

The sea urchin population explosion is a result of an imbalance in marine ecosystems, says Dr. Kumara, who heads the Department of Oceanography and Marine Geology at the University of Ruhuna. Over-fishing and depletion in numbers of the Puffer fish – one of the sea urchin’s chief enemies – could be one reason for the abundance of the urchin.

The Puffer fish blows a powerful jet of water to dislodge the urchin off rock surfaces to which it attaches with the help of a muscle in its body. The Puffer fish then turns the defenceless urchin over and attacks its soft underside, which is not protected by spines.

Puffer fish numbers have dropped as a result of over-fishing and export. Marine pollution and marine ecosystem degradation are other factors that can exacerbate the problem.

Dr. Sevvandi Jayakodi of the Department of Aquaculture and Fisheries, at the Wayamba University of Sri Lanka, has conducted research on sea urchins along the southern coast. She says there are signs that stretches of shallow sea facing beach-front hotels have been systematically stripped of sea urchins “This can cause a further imbalance to an already imbalanced ecosystem,” she warned, pointing out that sea urchins are the main grazers and cleaners of rocky shore systems.

In other countries, the sea urchin is regarded as a friend that has helped to control invasive giant seaweed. The sea urchin is native to our oceans, and not an alien invasive species. As a part of our marine ecosystem, their removal could have repercussions.

A colony of Sea Urchins in shallow waters

Learn about ‘The Environment and You’

To mark its 30th anniversary, the Environment Foundation Limited (EFL) is holding a series of public lectures on the theme “Conserving our Marine and Coastal Treasures”.

The first lecture was given by Dr. Terney Pradeep Kumara, who spoke about the “Sea Urchin Invasion.”
The next two lectures will be on “The Economics of the Environment”, on December 8, and “Responsible Wildlife Tourism”, on December 15.

The lectures are open to the public, and held in the auditorium of the Dialog Future World Building, on T. B. Jaya Mawatha, Colombo 10 (near Excel World), from 5.30 pm to 7.00 pm. For more information, call EFL on 011-4528483.

Indian smugglers take advantage of Sri Lanka’s liberal laws on export of marine creatures.

On Thursday, on the high seas off Kovilam, along the Northern coast, the Sri Lanka Navy intercepted a fishing boat and seized 20 gunny bags containing 996 kilos of dried sea cucumber. Four persons were arrested. The Navy believes the illegal cargo had been transferred to the fishing craft far out at sea with the assistance of Indian collaborators involved in cross-border racketeering.

Sri Lanka is known as a hub for the shipping of sea cucumber and sea horse – marine creatures prized by overseas buyers for their alleged medicinal properties.

Sea cucumber, also known as beche-de-mer, is used in Chinese medicine in East Asian countries, and demand is high. It is illegal to trade in sea cucumber and sea horse in India. In Sri Lanka, the marine creatures are treated as a fisheries resource and may be exported with a permit.

India’s Rameshwaran Island has a reputation for being a base for sea cucumber and sea horse smuggling.

Since the end of the war in the North and the East, smuggling activity has been on the increase.

Unsustainable fishing, according to Dr. Terney Pradeep Kumara, head of the Oceanography Department, University of Ruhuna, is threatening the survival of the sea cucumber.

The marine creature is a slow breeder, and it takes a long time for a population to regenerate after a spell of over-fishing. These creatures help maintain a balance in the marine ecosystem by keeping the sea floor clear of unwelcome algae and other edible but invasive creatures.

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Protecting Sri Lanka’s marine biodiversity is becoming increasingly difficult. As the Department of Wildlife Conservation (DWC) has no marine protection unit as such, the Navy could play a role in protecting Sri Lanka’s marine life and biodiversity.

Navy to the rescue

The following is a list of incidents this year in which the Sri Lanka Navy intervened to check illegal or harmful activity threatening the country’s natural resources and biodiversity.

Panchi: From a ripple in the ocean to a rattle on the Avurudu game board

After looking at Olinda – the shiny red and black seed used in the traditional Avurudu game Olinda Keliya, this week, Malaka Rodrigo explores the secret lives of cowries used in another Avurudu game — ‘Panchi Dameema’

“As New Year approaches, there is hardly a household where the rattle of the cowries and the clatter they make when tossed onto the inverted coconut shell, is not heard,” wrote Martin Wickremasinghe in his famous novel, Gamperaliya. The novel says some villagers were so addicted to the game that they began playing Panchi weeks before the Avurudu and continued even after the festive season. Some villagers even gambled their hard-earned money on a game of Panchi.One wonders how often the clatter of the cowries is heard this Avurudu season even in villages. Perhaps, like the novel Gamperaliya which speaks of the transformation of rural life, the traditional Avurudu has undergone a change with Panchi becoming a lost or vanishing game.

For an explanation of the game of Panchi, we need look no further than the novel: “Each of the players of two groups alternately took turns to toss the seven lead-filled little cowries, held in the hollow of a small polished coconut shell, onto the polished convex surface of a larger inverted half of a coconut shell. After each toss of the cowries, those that had come to rest with the flat surface upturned scored a point. The points scored by each side were registered by moving one or more of a set of pawns along a pattern of squares outlined on a wooden board, towards a home-base. The first team to take all the pawns to the home base won. Moving the pawns in the most advantageous way and avoiding elimination by pawns of the opponents, requires foresight, experience and shrewdness.”

The cowries used in the game are filled with lead to provide additional weight so that they do not spin abruptly. The ‘Panchi Petha’ — the board used for the game — was a household item, mostly in the southern parts of Sri Lanka in earlier times. Wooden boards were used in the olden days, but later cardboard Panchi Petha became popular.

Decades ago when I visited my village for Avurudu, I had the chance to play Panchi. But more than the game, the cowries attracted me. Most of the cowries had a white shell with a yellowish tint, but there were coloured ones too — some brown and some purple. The shiny shells made a pleasing sound when shaken inside the coconut shell. As children, we collected unbroken Panchi on the beach whenever we visited the seaside. We understood that Panchi was the shell of some sea creature, but knew nothing else.

“Panchi is the shell of a mollusc species called Cowry. It is a kind of sea snail that lives in shallow waters around the country and there are different species,” explained Dr. Malik Fernando, an expert on Sri Lankan sea shells.

The shell of the cowry is indeed the external skeleton or exoskeleton of the marine mollusc made of calcium carbonate. This serves not only for muscle attachment, but also for protection from predators. Ultimately the shell gives a beautiful structure that lasts even after the owner’s death. These cowry molluscs are scientifically classified as the family called Cypraeidae. There are around 250 cowry species in the world’s oceans. Experts believe there can be 20-0 cowry species found in Sri Lankan waters.

Dr. Fernando’s book “Shells of the Sri Lankan Sea Shore” mentions that there are cowries ranging in size from 1cm to 10 cm and the shell of the cowry grows in a spiral fashion like those of other snails until the animal reaches maturity. The shell is usually bordered by teeth on both sides. The exterior is smooth and highly polished. This is because the animal has a covering called a mantle, flesh that wraps around the entire shell. Each animal’s mantle is brilliantly coloured and is often more interesting than the shell itself. The mantle actually has finger-like projections all over it making the shell look like a sponge. When the mantle is touched, the animal withdraws, exposing the shell underneath. This natural camouflage is what makes cowries some of the hardest shells to find when they take refuge in the ecosystem they live.

Divers who often encounter live cowries in the moderately deep water around Sri Lanka, including the ocean around Colombo, claim that the animal is also beautiful like the shells itself. Cowries prefer to take refuge in coral reefs, the underside of boulders and mud-covered rocks where seaweeds abound. They become active only at night. Cowries feed mostly on tiny algae.

“The yellowish white form of the cowry shells usually used in the game of Panchi is the shell of a species called the Money Cowry,” Dr. Fernando said. It gets its name because in ancient times it was used as a form of money. The money cowries are usually smoothly ovate varying from pale whitish yellow to dark yellow with some grey banding across the central portion.

The mantle or the layer of flesh that covers the live Money Cowry is said to be grey-black with yellow streaks and spots. So they would look different on the ocean floor when alive. Because they have a fleshy mantle that covers the shell during the live stage, the shell is protected from predators though some develop mechanisms to penetrate them. Cowries have different ways of hiding from their predators, some burying themselves in the sand while others hide beneath rocks. Their camouflage also makes them hard to spot.

Apart from Money Cowrey, there are other varieties such as Cat or Kitten Cowrie, Grape Cowrie and Arabian Cowrie. So the next time you hear the rattle of a Panchi, spare a thought for the fascinating life of the live cowries that were once in those shiny shells.